Our overall objective is to define the mechanisms human dental plaque bacteria (specifically Streptococcus sanguis, Streptococcus miteor, Actinomyces viscosus and Actinomyces naeslundii) utilize to colonize the tooth surface. This requires a two phased study. First by characterizing the structure and specificity of the components produced extra-cellularly and/or on the bacterial surface which enhance their ability to adhere to the salivery pellicle. And secondly, the characteristics and identification of components from saliva that form the salivary pellicle and specifically bind to the bacteria.